The invention relates to an installation for investigating objects using magnetic resonance comprising a safety room which has gastight walls and a magnet system for producing a homogenous magnetic field in an investigational volume, the magnet system having a gastight outer shell which is penetrated in a shell region by feed-throughs into the interior of the magnet system.
An installation of this kind is known, for example, from the published patent application US 2005/200360 A1.
Research activities for the development of vaccines and therapies in conjunction with highly infectious viruses which can be transferred by aerosols, as well as research with gene manipulated and biologically, chemically or radioactively contaminated objects as well as poisonous chemical weapons (ABC weapons) all require a high level of safety precautions. Objects of this kind must, therefore, by investigated in a safety room from which no gas exchange is allowed to occur with the environment. The conditions for such safety rooms are, for example, described in the brochure “Laboratory Biosafety Manual”, Third Edition 2004, of the WHO, in particular on pages 2 and 3. In many cases, the requirements of Biosafety Level 4 described therein have to be fulfilled. For research on the aforementioned objects, among other things, measurements using magnetic resonance are of interest. Since devices arranged within the safety room can also become contaminated, these devices can no longer be used to investigate non-contaminated objects. Therefore, separate devices are generally required for the investigation of contaminated and non-contaminated objects. The acquisition of a plurality of devices for measuring magnetic resonance is, however, associated with considerable cost.
The maintenance of devices arranged in contaminated spaces represents an additional problem, since maintenance personnel have to spend time in the safety room during the maintenance procedure, for example when filling liquid helium for the superconducting coils of the device. This requires additional safety measures to protect the personnel (protective suits, disposal of the protective clothing, health monitoring of the personnel and the like) and involves considerable risks for the technical personnel, in particular since the risks associated with contamination are often underestimated on the part of the technical personnel. A large portion of the maintenance work is, therefore, generally carried out by scientifically trained personnel, whereby the maintenance costs are unnecessarily increased.
In particular, for example, for the investigation of gene manipulated animals extremely high safety precautions are required to prevent the escape of the animals. The animals are generally investigated in an anaesthetized condition. Should the animal regain consciousness prematurely, these gene manipulated animals have to be prevented from escaping.
In the aforementioned published patent application, the stated problems are solved by the magnet being located outside the safety room, but the investigational volume being located on the inside. This is achieved by a safety room comprising an extension which projects into the magnet system and encloses the investigational volume.
Such an extension is, however, topologically complicated and difficult to produce, since it has to remain sealed even in the event of accidents. Additionally, the design of the installation considerably deviates from previous MRI investigating rooms with integral radio frequency (=RF) shielding, which further increases the complexity and costs.
By far, the most frequent maintenance tasks by non-scientific personnel take place on the magnet system and it appears to be completely acceptable to design the installation such that it is only during such work that the safety room must not be entered.
It is therefore the object of the invention to propose an installation for investigating contaminated objects using magnetic resonance, in which simple maintenance of the magnet system is possible without risk of contamination for the maintenance personnel, which is as simple and robust as possible and which deviates little from standard investigating rooms.